This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is a series of observational studies to examine neural mechanisms underlying human face and object recognition in typically developing (TD) individuals and individuals with autism spectrum disorders (ASD). A significant number of research studies were previously conducted by this research team and others to determine brain mechanisms responsible for face processing. These studies have focused on obtaining qualitative measurements. The investigator for this project will use a quantitative and more predictive model to examine the process. The primary and secondary objectives are: 1) to examine neural mechanisms of visual object and face recognition and high level cortical plasticity in adults with TD and adults with ASD and related social developmental disorders and 2) to provide a baseline for future studies of neurological populations with object recognition deficits. The investigator proposes three separate studies. Each is described in detail and rationale is provided. Study I is designed to observe face recognition in the typical brain through a combination of model-based behavioral and functional Magnetic Resonance Imaging (fMRI) studies. It will focus on the "Fusiform Face Area" (FFA), an area of the brain that plays a key role in human face perception. In study II, the investigators will infer differences in neural processing by contrasting the results of fMRI and observed behavior between individuals with TD and ASD. In study III, they will test whether these processing differences between TD and ASD individuals extend to the learning of novel object classes. Each hypothesis is clearly stated and the investigator's approach to testing them is detailed and well documented.